Set top box



FIG. 1 is a left front perspective view of a set top box showing my design;

FIG. 2 is a right front perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof. 

The ornamental design for a set top box, as shown. 